Left Ventricular Performance During Propofol or Methohexital Anesthesia

Abstract

Using gated radionuclide ventriculography and invasive cardiac monitoring, the effects of propofol and methohexital on left ventricular volumes and function were investigated in 22 unpremedicated patients (ASA physical status III, 50-78 yr) with chronic coronary artery disease (NYHA class II-III). Anesthesia was induced with either propofol or methohexital (2 mg/kg), followed by a maintenance infusion of 100 micrograms.kg-1.min-1. Vecuronium (0.05 mg/kg) was administered and ventilation (FIO2, 1.0) was manually controlled (FECO2, 0.04-0.05). Data acquisitions were serially obtained over 15 min. Propofol and methohexital anesthesia caused an average 15% decrease in mean arterial pressure, associated with a 20% decrease in cardiac index without a decrease in systemic vascular resistance index. It is interesting that the determinants of these hemodynamic effects were different. Heart rate did not change during propofol infusion despite the decrease in mean arterial pressure, whereas heart rate increased during methohexital infusion. In the propofol group, the decrease in cardiac index was associated with decreases in indicators of preload (end-diastolic volume and pulmonary capillary wedge pressure), whereas end-systolic volume and global ejection fraction did not change statistically. In the methohexital group, the decrease in cardiac index was associated with a decrease in global ejection fraction and an increase in end-systolic volume, whereas indicators of preload remained unchanged. It is concluded that methohexital reduces left ventricular performance. In contrast, propofol preserves left ventricular performance despite a likely negative inotropic effect.

Changes in left ventricular end-diastolic area, end-systolic wall stress, and fractional area change during anesthetic induction with propofol or thiamylal

“…Propofol was infused in already anesthetized patients in the former study and in awake patients in the latter. We used propofol in awake patients, and our results are compatible with Lepage's results [5,10]. We measured EDA using TTE with automated border detection.…”

“…The LV enddiastolic volume (EDV) obtained from the modified Simpton's rule with TEE remained unchanged with propofol and thiopental [2,12]. Lepage et al [5,10], using gated radionuclide ventriculography, however, obtained decreased EDV with propofol. Propofol was infused in already anesthetized patients in the former study and in awake patients in the latter.…”

“…Several methods have been used to assess the effect of anesthetics on LV contractility in humans. Mulier et al [2,12] used the modified end-systolic pressure-volume relationship, whereas Gauss et al [1] and Lepage et al [10] used the end-systolic quotient. These studies showed that propofol was more potent than thiopentone with regard to depression of contractility.…”

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nisms have been postulated, including a reduction in myocardial contractility, alterations in loading conditions, and changes in the central nervous system [5][6][7][8][9][10][11]. In humans, left ventricular (LV) performance has been assessed during infusion of propofol using transesophageal echocardiography (TEE) [2,12].

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Cortisol Lowering Action and Cardiovascular Stability of Etomidate: A Comparison With Propofol in Controlled Hypertensives

“…8,9,10,11 Various mechanisms are proposed for these differences in haemodynamic response of these drugs. Propofol has been shown to decrease preload, 12 afterload, 13 and myocardial contractility. 14 Several investigations have attributed the arterial and venous dilating properties of propofol with direct effect on vascular smooth musculature.…”